Do I have to hone and deglaze cylinder?

kgb117

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I have a 2012 RMK with 3800km. Im doing its first top end replacement. Service manual says I should hone the cylinder to allow the rings to seat properly and increase oil retention. Just wondering if this is usually done after cylinder damage, or every top end change.
 

ippielb

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Every top end change should have a cylinder hone done. The rings will wear into the cylinder to create a good seal.

Once you put out new rings into the cylinder if you don't hone for crosshatching you won't set the rings, it will be too "slippery" and you will experience blow by. Lower compresssion, and a less responsive/more sluggish sled.

if there is no damage on your cylinders, just do a light hone, with a lot of two stroke oil. You don't want to do such a deep hone on a high mileage cylinder and risk your nicasil coating.

also be careful around the base of your cylinder, you only need to hone where the rings will be able to touch.
 

neilsleder

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Lots of guys say you don't with nikasle cylinders. But I would just for peace of mind. But then again lots of guys will reuse the gaskets and o-rings lol


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tex78

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Problem with nicaseal is it isn't very thick, and all ready worn down some from old rings and pistons

So if u hone it it takes more away and you get more piston to cylinder wall clearance ( piston slap)



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Lund

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I have a 2012 RMK with 3800km. Im doing its first top end replacement. Service manual says I should hone the cylinder to allow the rings to seat properly and increase oil retention. Just wondering if this is usually done after cylinder damage, or every top end change.

Here is my advice, you can go either way. Here why, Nikasil chroming is a VERY hard surface lining your cylinder. The piston kit will come with Nikasil match rings, very important. You can not use just any rings in a Nikasil cylinder.
The rings are softer then the Nikasil chroming and are design in such a way that they will conform to the cylinder imperfection quickly.
Now here is the bigger question to answer, "break in", the most crucial time in a new motor life. If you hone out the cylinder you will wear in the ring quickly in to the cylinder conformity. If you do not hone, the rings will conform but will take longer to do so.
Here is the catch...the longer you take to seat the rings the more likely hood they have on just "glazing" this means they will never conform and like mentioned by ippielb, you will end up with a low compression motor with blowby into the crank case.
Now on the other hand if you hone out the cylinders to look like a machine crosshatch like Tex mentioned you are now wearing into a very thin surface and stand a chance on flaking the Nikasil, especially around the ports. Also during break in the rings will wear very quickly as they are softer and if they do not wear in the machined cross hatch within a few miles to seat the rings the cross hatch will never wear and the ring will wear prematurely(remember rings are softer)

The trick and what I recommend is a very LIGHT hone passed through, just enough to help the rings seat but not enough to kill the rings. What your looking for is a lightly scratch surface where the rings ride, nothing else.
Then once together and all fluids are up, do not run it till you can actually break in the rings. That should be done ASAP at WOT interval's, 8-10 times with a 10sec load applied and 1min cool down period approx.
If it grenades the job wasn't done right and it would of grenade sooner then later. So do this near your vehicle. A 2stroke CAN be ran at WOT for long distances without issues if all is good, properly broke in.
 

Lund

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Just wanted to add, if you decide on honing the cylinders, use a Ball hone and not a Rigid hone. Rigid hones are suitable to use on NEW cylinders and machine shop's used them after machining. A ball hone is what you would use on a USED cylinder, all you want is to bust the glaze not reshape the cylinder. The ball hone will conform to the cylinder but a rigid hone will not.
 

Lund

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Ball hone not hard on the edges of the ports?


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No, the ball hone won't damage the ports. But you need to use the proper fitting hone for the bore.
I like to also chamfer the port edges before I hone, its just a precaution for the rings to prevent catching. I doit with a very small file.
 
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